Solution of data encryption and authentication for databroadcast based on UDP/IP

Conditional access system is an important unit for databroadcast,in ordertosolve the permission problem of CA system based on UDP/IP.USBkey is used as a client authentication media to provide a new certification solution of the binding of the symmetry and non-symmetry schema,which offer a high safety to get data integrity and have a success application in CCTV databroadcast.